Horn



Sept. 14, 1937. F. w. BILLIG ET Al.

HORN

Filed July 31, 1934 /Nvf/vrfzs WIT/V535 Patented Sept. 14, 1937 HORNFred William .Billig and Lloyd Elmer Johnson,

Jackson, Mich.,

assignors to; The Sparks- Withington Company, Jackson, Mich., acorporation of 'Ohio Application July 31, 1934, Serial No. 737,746

2 Claims.

This invention relates to improvements in signaling devices commonlyknown as horns for power driven vehicles and which involve the use of amagnetically actuated diaphragm.

The main objects of this invention are to provide a sound signal or hornof the magnetically actuated diaphragm type, that is especially light,durable and economical in construction; that is long lived and reliablein operation; that Vmay be readilyassembled and permanently adjusted;and that, at the same time, has exceptionally iine tone qualities.

In carrying out the above mentioned objects, we have by improvementsinthe design, construction and arrangement of the various elements ofour improved horn reduced the number of parts vfrom about one hundredfifty-one employed in kpreviously constructed horns of the same type tosubstantially forty-one, ora reduction of approximately seventy-threepercent. while the weight of our novel horn is substantially twelve andonehalf percent. Aless than that of similar types of conventionallyAconstructed devices.

The specic manner in which the above mentioned improvements areobtained, as well as other objects and advantages .pertaining to thesize and form of the various parts of the structure, will more fullyappear from the following description, .taken in connection with theaccompanying drawing, in which: f

Figure 1 is a perspective view of a horn embodying the various featuresof this invention, illustrating the same with the motor cover removed;

Figure 2 is a transverse sectional view taken substantially on line 2 2,Figure 1, and illustrating the motor cover assembled in operativeposition;

Figure 3 is a detail horizontal sectional View taken on line 3 3, Figure2;

Figure 4 is a perspective view of the armature assembly;

Figure 5 is a detail transverse sectional View taken substantially inthe plane of the line 5-5, Figure 2;

Figure 6 is an enlarged detail side elevation of the adjacent coactingend portions of the armature and eld studs;

Figure 7 is an enlarged detail sectional View taken on line 1 1, 'Figure5; and

Figure 8 is a perspective view of a shim used to adjust the magnet corerelative to the armature.

The signaling device comprising thisinvention and as shown in thedrawing, comprisesa pressed metal rear diaphragm housing sectionI,having vits central portion pressed laterally to form .an integralsubstantially cylindrical cup-.shaped member 2, said member being formedatits central portion with an opening 3, for the reception of anelectro-magnet or a magneticeld presenty ly described. 'I'he diaphragmas 5 is clamped between the rear diaphragm housing I and a frontdiaphragm housing section 6, by bolts 'I extending through alinedgholesprovided in the marginal portion of the housing sections I .and .6 anddiaphragm .5, Y and nuts 8 which are screw threaded on-zthe bolts ,'I.-Thebolts 'I are ,arranged in uniform circumferential spacedv relationandthe nuts 8 coact with the bolts for securely and rigidly clamping thesemembers together. The. front diaphragm housing section 6 has the centralportion thereof pressedlaterally to form an integral substantiallycup-shaped member 9 arranged in` opposed relation to the central portion2 of the reardiaphragm housing section to form a diaphragm chamber J0,therebetween. The portion 9.of the front housing section is Vprovidedwith a central opening II defined by an outwardly extending annularflange I2 which supports a projector I3 of any`desired contour, .andwhich may be ref movably secured to the flange I2 by any suitable meansas screws I4.

Thediaphragm 5 extends as shown in Figure .2 through the chamber I0intermediate the front and rear walls thereof, and is preferably ofserpentine formation in cross-section for the reason that the diaphragmwhen so formed maybemade from Vthinner stock with the resulting savingin cost thanv when formed substantially.. hat, and further, when the'diaphragm is so formed, it is found to haveimproved tone qualities.-

The electro-magnet or magnetic eldpreviously referred to is preferablyofthe form best illustrated in Figure 2, .and comprises a core 4 ofsolid stud formation having an enlarged vflange or head I6, at one end,whilethe opposite end portion lof the core or eld stud is vreduced indiameterand externally'threaded to receive a nut =Ii1 thereon. l

The field coil I8 is mounted on thestud 4 between head IB and thethreadedportion, 'and is .built up of coiled wire in the well knownmanner, andis taped or otherwise insulated from the stud 4. The stud 4and coil I8 arefsecured to the rear diaphragmhousi-ng section `l'bymeans :of a U-shaped bracket or yoke lf9kpositioned-fat the rear foftherear diaphragm housing section I. The .legs .of theyoke kextend-through :the opening 3 of said section and have the outer end portionsthereof extended outwardly from the remaining portion and positionedadjacent the inner or forward face of the housing section portion 2. Theyoke I9 is permanently secured in position to the housing section I,preferably by spot welding, so as to form a substantially solid unitarystructure of maximum strength.

The central or transverse portion as 20 of the yoke, as hereinbeforehinted, is positioned at the outer or rear side of the rear diaphragmhousing section I in considerable spaced relation thereto, and isprovided with a central opening 2| for the reception of the reducedthreaded portion of the stud 4. The hereinbefore mentioned nut I1 isscrew threaded on the outer end of said threaded portion of the stud 4and coacts with the shoulder as 4 formed by the reduced portion of thestud for securely clamping the stud to the yoke.

It is desirable, as will be more readily apparent farther on in thedescription, that the coil I8 and field stud 4 be maintained againstrotary movement as the nut I1 is being threaded to the clampingposition, and for this purpose the threaded portion of the field stud isprovided with a flat surface as 22 along one side thereof, While theopening 2| is provided with a similarly flattened side adapted tocooperate with said flattened portion of the stud.

The yoke I9 is preferably, in order to obtain maximum strength withminimum weight, a metal stamping. Further, the yoke is formed from asolid piece of hot or cold rolled steel so as to provide a supportconnected directly to the leld stud which has high permeabilitycharacteristics which reduces arcing between the contacts 56 and 51,presently described, and thus eliminate the necessity for a condenseracross said contacts.

The yoke I9 has the transverse portion 20 thereof provided with a pairof outwardly extending ribs 25 positioned one adjacent either sidethereof, These ribs 25 not only reinforce the yoke member, but also formguide stops yadapted to maintain a cover attaching bracket 26 againstrotation as the nut I1 is screw threaded to the clamping position. Thisbracket 26 is in this instance, a U-shaped slightly resilient memberhaving one leg thereof mounted on the portion 20 of the yoke I9intermediate the ribs 25 and is provided with an aperture adapted toreceive the reduced threaded portion of the magnet :stud 4,therethrough. The other end of the bracket terminates above the kfieldstud 4 in spaced relation thereto and is provided with a threadedaperture arranged substantially coaxially with the eld stud 4 forreceiving a screw 21 which extends through a suitable opening providedat the center of a cover 28 for securing said cover in position forenclosing the rear diaphragm housing section I, yoke I9, and the memberscarried thereby. This cover 28 is an inverted cupshaped member havingthe marginal edge thereof flared outwardly for surrounding the marginaledge of the rear diaphragm housing section I, and adapted to engage themarginal `edge portion of the front diaphragm housing section 6 which,as shown in Figures 1 and 2, is slightly larger in diameter than that ofthe rear section I for the purpose of supporting the cover 28.

It will thus be seen that the cover 28 is-maintained against lateraldisplacement on the front housing section 6 by the engagement therewithhead 33 of the stud 32.

housing section I, While said cover is secured in position by the singlescrew 21. Further, by forming the bracket 26 slightly resilient, it willbe observed that when the screw 21 is threaded inwardly for tightlysecuring the cover in place, the strain which might otherwise beproduced upon the eld stud 4 and yoke I9, will be entirely absorbed bythe bracket and thus prevent the adjustment of the horn from beingdisturbed and the elimination of any distortion of the horn which mightotherwise be produced if a rigid connection was provided for securingthe cover in place.

The hereinbefor-e mentioned armature 24 comprises, in this instance, apair of substantially rectangular plates 3|) and 3| secured together insuperposed relation by spot welding, rivets, or the like. The innerplate as 30 is of slightly less length than the outer plate 3| and isadapted to extend rearwardly intermediate the legs of the yoke I9, Whilethe other plate 3| extends outwardly at either end some distance beyondthe plate 30 into overlying relation with the corresponding legs of thebracket I9, as clearly illustrated in Figures 2 and 4.

The plates 30 and 3| are provided with alined central openings for thereception of the armature stud 32 which is provided at one end with anenlarged flange portion or head 33, while the other end as 34 of thestud is reduced in diameter and externally threaded for the reception ofa nut 35. The armature plates 3E) and 3| are secured to the diaphragm 5by means of the armature stud 32 which extends through a suitablelopening provided at the center of the diaphragm 5 in coaxial relationwith the field stud 4. The plates 30 and 3| are maintained in spacedrelation to the diaphragm 5 by means of a washer 36 mounted on the stud32 intermediate the plate 3| and diaphragm 5. The forward or outer endof the stud 32 supports a resonator 31 which is maintained in spacedrelation with the diaphragm 5 by a pair of Washers 38 and 39. The plates30, 3|, stud r32, resonator 31, Washers 35, 38 and 39,

and the diaphragm 5 are rigidly and tightly sesi cured together and toeach other by means of the nut 35 and a lock washer 49 coacting with theThe head 33 is positioned adjacent the smaller armature plate 30 inclose proximity to the head I6 of the eld stud 4 for 5 movement into andout of contact with said head I6 during the flexing of the diaphragm 5.

It will be observed that the stud 32, armature plates 39 and 3|,diaphragm 5 and resonator 31 will be rigidly secured together by the nut35 for I" unitary movement while the thickness of the washer 36 is suchas to normally maintain the outer end surface of the head 33 in theplane of or slightly at the rear of the rear or`outer surface of thecentral portion .2 of the rear diaphragm housing section I. The lengthof the central portion of the eld stud 4 relative to the yoke I9 is suchas to maintain the head I6 of the stud 4 normally in slightly spacedrelation with the head 33 of the armature stud 32 so that the head 33 ofthe armature stud will strike against the head I6 of the eld stud whendrawn toward the eld stud upon energizing the field magnet bycurrentflowing through the coil I8.

Further, the thickness of the head 33 and armature plate 30 areY suchthat when the head 33 is in contact with the head I6, the armature plate3| will almost, but not quite, contact with the adjacent portion of thelegs of yoke I9. with the "peripheral -edge of the rear diaphragm l Itwill thus be seen that inasmuch as the stud Cil comes energized by thecurrent passing -through the coil I8, with the result that a maximumamount of magnetic force will be exerted upon the Aarmature for a givenrcurrent passing .through the coil.

By referring to Figure 6, it will be observed that the contactingsurface of the head I6 is ,formed substantially flat and normal to theaxis of the stud 4, while the contacting surface of head v33 is slightlyconvex, so that there will always be a uniform surface contact of thestud members, even though the armature stud 32 may be moved or tiltedout of axial alinement with the vfield stud 4, due to an uneven flexingof diiferent portions of the diaphragm 5.` This arrangement oi thecontacting surfaces of the heads I6 and 33 also insures a uniformpredetermined vibratory movement Vof the diaphragm and armature assembly24,.

Itis very essential in this horn that the normal clearance between thearmature stud 32 and eld stud 4 be very slight, and this clearance isnecessarily conned between very close limits to obtain the maximumefficiency and tone qualities of the horn. This clearance can beaccurately obtained and permanently maintained in the present structurein a very easy andeflicient manner, as follows:

The gap between the heads I6 and 33 is obtained by rst inserting athickness gaugecorresponding in size to the required gap between theheads I5 and 33. This is readily accomplished as illustratedby brokenlines in Figure 5, bypass ing the gauge, when the cover 28 is removed,over the top or rear surface of the central portion 2 of housing I, andbetween the legs of the yoke I9 until the end of the gauge rests uponthe lower or forwardly positioned head 33, which, as previously stated,is in substantially the same plane as said surface of the housingsection. The eld stud I4 is then released by the screwing of the nut I1outwardly and moved into engagement with the gauge G, after which a shimas 42, or possibly a plurality of shims, of required thickness forspacing the head I6 from the head 33 is inserted over the coil I8 andbetween the eld stud shoulder 4' and the adjacent portion of the yokeI9. The stud 4 is then securely and rigidly clamped to the yoke by screwthreading the nut tightly against the yoke or bracket 26.

As it usually requires the trying of shims of different thicknessesbefore obtaining the proper adjustment of the stud 4, it will now bereadily understood that some means, as the flattened portion 22 of thestud 4, is necessary to maintain the stud and particularly the coil I8mounted on said stud, from turning to prevent breaking or injuring theelectrical connection between the coil and associated terminals as thenut I1 is screw threaded toward and from the clamping position. Anautomatic circuit breaker as is usual in horns of this type is providedwhereby the field coil I8 is caused to be energized intermittently. Thiscircuit breaker provided herewith is of novel construction in that it iscomposed of a very lfew simply constructed parts. Further, the circuitbreaker is quickly and readily adjusted .by the manipulation of but onemember, whereas, the manipulation of two or more members-is usuallyrequired in horns of this type as formerly con-.

structed. As illustrated in Figures '1, 5 and 7, two contact plates 44and 45, two terminal plates 45 and 41, and a supporting bar 48aresecured together by screws 49. The contact plates 44 and 45 and thesupporting bar 48 are maintained in electrically insulated spacedrelation with each Vother by means of insulating plates 5i) and .tub-

ing 5I composed of any suitable insulating material. One of the contactplates as 44 and the terminal plate as 4'6 are mounted in contact witheach other, while the contact plate 45 is maintained in electricalconnection with the other terminal plate as 41 Aby the screws 49 whichare screw threaded in the contact plate 45. This circuit breakerassembly is mounted in the dia-v phragm chamber I0, at one side of thearmature resilient member and extends transversely of the contact plates44 and 45 with the ends thereof extending beyond the sides of saidcontact plates. The supporting bar has .either end thereof .permanentlysecured by a rivet 54, or its equivalent, to

the housing section I at a respective side of the opening 53.

The contact plates extend radiallyinwardly from the supporting bar andhave coacting contact members as 56 and 51 secured respectivelytherewith. The lower or forwardly positioned contact plate as 45 is arelatively short, thick inflexible member, While the other contact plate44 is a relatively thin, flexible member, and extends inwardly beyondthe contact plate 45 in a plane over or rearwardly of the armatureplates 30 and 3|.' The inner end of the contact plate 44 terminates inthe path of movement of a lug or projection as 30 secured to or madeintegral with the armature plate 30. The contact points 56 and 51 arenormally maintained in contact with each other, but the flexible contactplate 44 is so positioned relative to the armature plates that when thearmature assembly is drawn inwardly or rearwardly as the eld coil isenergized, the contact plate 44 will be engaged by the lug 36' andflexed upwardly or rearwardly thereby sufficiently to move the contactpoint 56 out of engagement with the-contact point 51 to break thecircuit passing therethrough.

To obtain the correct adjustment of the contact plate 44 relativek tothe armature plates 30 and 3|, we have provided a screw member 58 whichis screw threaded in that `portion as `2' of the central portion 2 ofthe rear diaphragm housing section I which overlies the contact plates44 and 45 and which, in this instance, is pressed outwardly orrearwardly slightly to receive the plate 44 and permit the free iiexingthereof. The inner end of the screw 58 is maintained in electricalinsulated relation with the contact plate 45 by the adjacent insulatingmember 50 which is extended inwardlyover the contact plate asillustrated in Figure 5. The contact plates 44 and 45 are assembled onthe' supporting bar 48 in such a manner that the contact points 56 and51 will normally remain in engagement with each other, while the contactplate al is normally maintained by the supporting bar 48 in considerablespaced relation with the armature plates, 5 so that,in order to bringthe contact plate 44 into correct relation with the armature plate 3U,

it is only necessary to move the inner ends of the f contact plates 44and i5 outwardly or frontwardly towards the armature plates.

l This movement of the plates is effected by screw threading theadjusting screw 58 inwardly, inasmuch as the inward movement of thecontact plates is permitted by the flexing 0f the supporting bar 38, andthe contact plates may be 15 maintained in the adjusted position by alock nut 59 screw threaded on the adjusting screw 58.

The horn is also provided with a pair of terminal members as 6i which,in this instance, comprises a pair of spring members connected 20 to therear housing section l in insulated spaced relation to each other and tosaid section by a rivet 62, or its equivalent, and insulatingmember 63.One of the terminal members 6l is connected in the usual manner with oneend of the eld coil, while the other terminal member is oonnected withone of the terminal plates as dt, the other terminal plate 4l beingelectrically connected with the other end of the coil i8.

Although we have shown and described a spe- 30cic structure, We do notwish to restrict ourselves to the details or form of said structure asvarious changes may be made within the scope of the appended claims.

We claim:

35 1. A sound signal comprising a sheet metal diaphragm housing section,a diaphragm mounted on one side of said section, an armature secured tosaid diaphragm, said section having a substantially central opening, anelectro-magnet 40 mounted on the other side of said section in operativerelation with said armature, said section having a second opening spacedlaterally from the rst named opening, the portion separating saidopenings being offset in a direction away from said diaphragm, a circuitbreaker for intermittently breaking the circuit to said electromagnet,support means for resiliently securing one end of said circuit breakerto said housing section within said second named opening, the other endof said circuit breaker extending in underlying spaced relation withrespect to said offset portion and into operative relation with saidarmature, and means supported by said oiset portion and engaging thecircuit breaker for adjusting said circuit breaker relative to saidarmature.

2. In a warning signal of the class wherein a diaphragm housing sectionprovided with a substantial central opening has a diaphragm connectedtherewith to extend across said opening at one side of the section, anelectro-magnet including a core is mounted on the other side of saidsection with said core in co-axial relation with said central opening,and wherein said diaphragm has an armature connected therewith incooperative relation with said core, said signal being characterized bysaid housing section having a second opening spaced laterally from thecentral opening and a circuit breaker comprising two contact plates forintermittently breaking the circuit to said electro-magnet, supportmeans fixedly secured to said housing section at two points disposed atopposite sides of said second opening, said support means beingconnected with the contact plates in insulated spaced relation theretofor securing said plates to said housing section within said secondnamed opening, one of said contact plates being a relatively flexiblemember and extended into operative relation with said armature, andmeans supported by the housing section and engaging the other contactplate for ladjusting said circuit breaker relative to the armature.

FRED WILLIAM BILLIG. LLOYD ELMER JOHNSON.

